Nutrition 2420 Chapter 11

What are some new ways to lose weight mentioned?

EndoBarrier

Aspire Assist Pump

What 3 things should be included when determining if body weight is healthy?

BMI (Body Mass Index)

Body composition (if possible)

Fat distribution pattern

What is BMI?

Body Mass Index

What is the formula for BMI?

BMI = weight (kg) / height (m)²

Why is BMI considered a limited tool?

It does not consider:

Body composition

Fat patterning

Ethnicity

Age

What does BMI measure well?

It's a simple general estimate of body weight relative to height

What is considered underweight in BMI classification?

BMI < 18.5

What does being underweight indicate?

Too little body fat to maintain health

What is the healthy BMI range?

18.5-24.9

Why is the healthy BMI range important?

It has the lowest disease risk

What is considered overweight in BMI classification?

BMI 25-29.9

What does overweight indicate?

Moderate excess body fat

What is obesity defined as in BMI?

BMI ≥ 30

What does obesity indicate?

Excess body fat that negatively affects health

What are the classes of obesity?

Class 1: 30 to <35

Class 2: 35 to <40

Class 3: ≥40

What is body composition?

Measurement of body fat and lean body mass

How is body composition typically expressed?

As % body fat

What is one method used to measure body composition?

Underwater (hydrostatic) weighing

How does underwater weighing work?

Compares body weight on land vs. body weight in water

What is another method to measure body composition?

Skinfold measurements

What do skinfold measurements assess?

Subcutaneous fat

What is Bioelectrical Impedance Analysis (BIA)?

A method that uses a low-level electrical current through the body to estimate body composition

What is Dual X-ray Absorptiometry (DXA)?

A method using X-rays to differentiate between bone, lean tissue, and fat

What is the Bod Pod?

A body composition method based on air displacement

How long does a Bod Pod test typically take?

About 3 minutes inside the pod

What is fat distribution pattern?

How body fat is distributed throughout the body

How is fat distribution commonly measured?

Waist circumference

What is apple-shaped fat distribution?

Fat stored in the upper body

Higher risk for chronic diseases

What diseases are linked to apple-shaped fat distribution?

Type 2 diabetes

Heart disease

Hypertension

What is pear-shaped fat distribution?

Fat stored in the lower body

What is the disease risk associated with pear-shaped fat distribution?

No significant increased risk for chronic diseases

What waist circumference is considered high risk for males?

> 40 inches

What waist circumference is considered high risk for females?

> 35 inches

What type of fat is increased with high waist circumference?

Visceral (abdominal) fat

What is visceral fat associated with?

↑ Cholesterol & LDL

↓ HDL

Insulin resistance

What diseases are linked to high visceral fat?

Cardiovascular disease (CVD)

Hypertension

Type 2 diabetes

What determines whether a person gains or loses weight?

Energy balance

What is energy balance?

The relationship between energy intake and energy expenditure

What contributes to energy intake?

Food and beverages

What contributes to energy expenditure?

BMR (Basal Metabolic Rate)

Physical activity (PA)

Thermic Effect of Food (TEF)

What other factors influence body weight besides energy balance?

Genetic

Cultural

Metabolic

Economic

Physiologic

Social

Behavioral

Why is overweight/obesity considered multifactorial?

It results from multiple contributing factors, not just one

What is Basal Metabolic Rate (BMR)?

Energy used for basic (resting) body functions

What percentage of total energy expenditure does BMR account for?

~60-75%

What is Physical Activity (PA) energy expenditure?

Energy used for all activity beyond resting

What percentage of energy expenditure does physical activity account for?

~15-35%

What is the Thermic Effect of Food (TEF)?

Energy used to digest, absorb, transport, and store nutrients

What percentage of energy expenditure does TEF account for?

~5-10%

How does lean body mass affect BMR?

More lean tissue increases BMR

How does age affect BMR?

BMR decreases ~3-5% per decade after age 30

What factors determine physical activity energy expenditure?

Number of muscle groups used

Intensity

Duration

Body size

Which macronutrient has the lowest TEF?

Fat

Which macronutrient has the highest TEF?

Protein

How many kcal/kg/day does lean tissue use?

13-28 kcal/kg/day

How many kcal/kg/day does adipose (fat) tissue use?

~6.5 kcal/kg/day

What increases BMR?

↑ Lean body mass

↑ Height

Male gender

↑ Thyroid hormone

Pregnancy & lactation

Stress, fever, illness

Stimulants (caffeine, tobacco)

What decreases BMR?

↓ Lean body mass

↓ Height

Female gender

Aging

What is the most important determinant of BMR?

Lean body mass

In weight loss, what happens to fat mass and lean body mass?

Both decrease

What happens to BMR during weight loss?

It decreases

What happens to energy cost of physical activity during weight loss?

It decreases

What happens to TEF during weight loss?

It decreases (due to lower food intake)

Why must reduced calorie intake be maintained after weight loss?

To maintain the lower body weight

What commonly happens after people finish a diet?

They increase intake again → weight regain

What part of the brain regulates hunger and satiety?

Hypothalamus

What types of substances regulate hunger and satiety?

Proteins and hormones

What is ghrelin?

An appetite stimulant hormone

When does ghrelin increase?

After weight loss

What is neuropeptide Y?

An appetite stimulant

Name appetite-suppressing hormones.

Peptide YY (PYY)

Leptin

Cholecystokinin (CCK)

Serotonin

What happens if there are defects in hunger/satiety hormones?

Energy balance may be disrupted

What physiological factors suppress appetite?

Stomach expansion

Nutrient absorption in small intestine

↑ Blood glucose

What stimulates appetite physiologically?

Endorphins

↓ Blood glucose

Where are endorphins secreted from?

Pituitary gland

How does income relate to obesity rates?

Lower income is associated with higher obesity rates

Why does lower income increase obesity risk?

Less access to healthcare

Less access to health information

What is a food desert?

Areas with limited access to affordable, healthy food

What types of food sources are common in food deserts?

Fast food restaurants

Convenience stores

What barriers contribute to food deserts?

Transportation issues

Personal safety concerns

What is required for healthy weight change (loss or gain)?

Gradual change in energy intake

Regular physical exercise

Behavior modification

Why is exercise important in weight management?

It is critical for long-term weight maintenance

What are key goal-setting strategies for weight management?

Specific

Reasonable/attainable

Measurable

What is important when working toward weight goals?

Monitoring progress

What are key strategies for healthy weight loss?

Reduce portion sizes

Decrease high-fat/high-energy foods

Eat low energy-dense foods

What BMI defines underweight?

< 18.5 kg/m²

Why can being underweight be unhealthy?

Increases risk of infections and illness

What are causes of being underweight?

Genetics

High physical activity

Low calorie intake

Smoking

Disease (malabsorption, cancer, AIDS)

Disordered eating

How many extra calories are recommended for weight gain?

500-1000 kcal/day

What energy balance is required to gain weight?

Positive energy balance

What types of foods should be emphasized for weight gain?

Energy-dense and nutrient-dense foods

What eating pattern helps with weight gain?

Eating frequently throughout the day

What percent of energy intake should come from fat during weight gain?

15-30%

Why should tobacco be avoided during weight gain?

Decreases appetite

Increases BMR

What type of exercise is recommended for weight gain?

Resistance training

What are major health risks associated with obesity?

Hypertension

Dyslipidemia

Type 2 diabetes

Heart disease

Stroke

Gallbladder disease

Osteoarthritis

Sleep apnea

Certain cancers

What reproductive and pregnancy issues are linked to obesity?

Infertility

Gestational diabetes

Premature fetal death

Neural tube defects

Labor/delivery complications

What neurological/mental health conditions are linked to obesity?

Depression

Alzheimer's disease

Dementia

Cognitive decline

What percentage of U.S. adults were obese (2018)?

42.4%

What is a common calorie deficit recommendation for weight loss?

500-1000 kcal/day

What type of exercise is recommended for obesity treatment?

Regular exercise (gradually increased; doesn't require a gym)